Just found this out, so i am answering my own question :)
Use a comma where you would normally use a colon. This can be a problem for named instances, as you seem to need to specify the port even if it is the default port 1433.
Example:
Provider=SQLOLEDB;Data Source=192.168.200.123,1433; Initial Catalog=Northwind; User Id=WebUser; Password=windy"